Methylphenidate hydrochloride (HCl) and dexmethylphenidate hydrochloride both have the empirical formula C14H19NO2.HCl. Methylphenidate HCl is a racemic mixture of d,l-threo-methyl α-phenyl-2-piperidineacetate hydrochloride. Several commercial products, including, e.g., Ritalin®, Daytrana™, and Metadate™ contain methylphenidate HCl as the active drug. Dexmethylphenidate is the d-threo-enantiomer of racemic methylphenidate hydrochloride [Focalin® product literature]. There are several commercial products which contain dexmethylphenidate as the active drug.
The use of the central nervous system stimulants methylphenidate and dexmethylphenidate for the treatment of such conditions as attention deficit disorder (ADD) and attention deficit hyperactivity disorder (ADHD) in adults and children has been described [see, Focalin®, Concerta®, Daytrana™ and Metadate® product literature]. This drug may also be used to treat depression and cognitive impairment following Traumatic Brain Injury [See, product literature for methylphenidate hydrochloride tablet which is commercially available from Lake Erie Medical DBA Quality Care Products LLC, and product literature of the other drug products identified herein].
Solid dose methylphenidate or dexmethylphenidate products are commercially available having an extended release profile of 8 hours according to the product label. These products include, e.g., Ritalin® LA and Methylin® ER tablets have product labels indicating that they must be swallowed whole without crushing or chewing. Liquid methylphenidate dosage forms have also been described which are predominantly designed for children, including children as young as 3 years old who have difficulty swallowing solid dosage forms.
There remains a need for a quick-acting, stable, extended release methylphenidate product which can be conveniently delivered in a form suitable for patients who have difficulty swallowing solid tablets and capsules.